Durable floor marking tapes that will withstand heavy traffic under industrial conditions are desired for use in factories. Heavy traffic means subject to forklift wheels going straight, turning or pivoting, cleaning scrubbers, skids being dragged, hand carts, pallet jacks, metal shavings or debris embedded into wheels, and frequent foot traffic. The tape should be easy to install in straight lines, repositionable yet build sufficiently high adhesion. It should be removable without leaving adhesive residue that cannot be easily cleaned. Typically, it is only for indoor use and available in multiple colors and capable being printed with various graphics such as diagonal stripes. Occasionally it is used in discontinuous shapes (e.g., corner L's, T's, dots, dashes, etc.) and sometimes floor signs are made from it.
Current products on the market fall within two categories. One product category comprises a thinner (typically less than 0.008″ thick), inexpensive, polyvinyl chloride (PVC) backed, self-adhesive tape. It may be self-wound (i.e., linerless) or it may be carried on a liner. This category of tape is generally stretchy, and it is usually pigmented within the PVC film backing for an overall color. It can also carry additional graphics that are surface-printed, such as diagonal stripes. The PVC backing typically contains a plasticizer which results in a conformable, somewhat stretchy tape.
The other category is a much thicker backed tape or extrusion. These are also made from plasticized PVC and can range from 0.020″ to 0.080″ thick. While they may be slit from sheets, typically tape products in this range are extruded at their finished width. Finished widths for tapes of both categories range from 2″ to 4″. The thicker category is usually extruded with a beveled edge profile to ease sliding or rolling traffic across its width.
The thinner tapes, being stretchy, are oftentimes quite difficult to apply in straight lines. In addition, to accommodate stretch that results from unwinding and laying the tape out, compensation is needed to allow recovery and avoid shrinkage and distortion after application.
Plasticizer compatibility with pressure-sensitive adhesives (PSA, the adhesive of choice for floor marking tapes) is also a problem with tapes having a PVC backing. Plasticizers tend to migrate out of the PVC backing and in to the PSA and if compatible with the PSA, they will overly soften the PSA reducing adhesion and, especially, shear resistance. If the plasticizer is not compatible with the PSA, then the plasticizer tends to accumulate at the interface of the PVC backing and the PSA resulting in delamination of one from the other upon aging and exposure to stress. While methods exist to accommodate plasticizer incompatibility, most require costly barrier coatings or expensive tightly specified compounds both of which add to overall product cost.
The thicker tapes are not as stretchy on application and can be applied in a straight line more easily than the thin PVC tapes, although in the case of extruded PVC the extrusion can take on a “set” resulting in curve and/or curl that must be accommodated. While quite rugged, the thicker tapes also present a higher profile to side loads, and as a result need to sustain much higher stresses. The same problem with adhesive degradation from plasticizer compatibility exists with the thicker tapes as with the thinner tapes.
Surveys of end-users of these products to mark industrial workplace floors have uncovered enormous user dissatisfaction with these products. Complaints include difficult and expensive installation, poor resistance to impacts, poor appearance from wear and dirt accumulation, a short useful life, and in the case of the thicker product, very high cost.